Railway Science (Biology – Cell : Basic Unit of Life) (Part-II)

A vacuole is a membrane-bound cell organelle that stores water, nutrients, and waste products. In animal cells - vacuoles are generally small and help sequester waste products. In plant cells - vacuoles help maintain water balance. Sometimes a single vacuole can take up most of the interior space of the plant cell.

Photosynthesis - The process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. Deplasmolysis - water rushes into the cell, causing the cytoplasm and plasma membrane to swell as water is stored in the vacuole.
Cytolysis (osmotic lysis) - Occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell.

Cellulose (most abundant organic molecule on Earth). Cytosol - The aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended. Cytoplasm - It is the main arena of cellular activities in both the plant and animal cells.
Glucose - During photosynthesis process, carbon dioxide from the atmosphere is taken in by leaves through stomata and used for making carbohydrates, principally glucose and starch.

Golgi apparatus is made up of a series of flattened stacked pouches called Cisternae. Endoplasmic Reticulum : An organelle that is responsible for the lipid synthesis and the protein modification.
Two types: Rough Endoplasmic Reticulum : It is a cell organelle that participates in the synthesis of enzymes and proteins, Smooth Endoplasmic Reticulum : It is a cell organelle that Synthesises glycogen, lipids, and steroids. Ribosomes : are the protein synthesising factory of a cell.

Nucleus (cell’s “command center” that stores DNA). Organelle - A small biological structure that performs a specific function inside the cell. Classified into three categories based on the presence or absence of membrane. Organelles without membrane : The Cell wall, Ribosomes (smallest cell organelle), and Cytoskeleton present in both prokaryotic cell and the eukaryotic cell. Single membrane bound organelles : Vacuole, Lysosome, Golgi Apparatus, Endoplasmic Reticulum present only in a eukaryotic cell.
Double membrane bound organelles : Nucleus, mitochondria and chloroplast found in eukaryotic cells only.

Connective tissue : This is a kind of biological tissue that supports, connects, or separates different types of tissues and organs of the body. Examples - Tendons, ligaments, cartilage and bone.
Epithelial tissue : They are formed by cells that cover the organ surface such as the surface of the skin, the airways, the reproductive tract, and the inner lining of the digestive tract.
Muscular tissues : A soft tissue that composes muscles. Examples - Skeletal muscle (voluntary muscles), and cardiac muscle (involuntary muscles). Nervous tissue : The main components are the brain, spinal cord, and nerves which regulate and control body functions.

Epithelium - A type of body tissue that forms the covering on all internal and external surfaces of your body, lines body cavities and hollow organs and is the major tissue in glands. Types : Simple (only one layer of cells), Stratified (more than one layer of cells) and Pseudostratified (closely packed cells that appear to be arranged in layers because they’re different sizes, but there’s actually just one layer of cells).

All blood cells begin their life as stem cells which mature into red blood cells, white blood cells and platelets.
Appendix - A vestigial hollow tube that is closed at one end and is attached at the other end to the cecum, presents in the lower right part of your belly (abdomen).
Spleen - An organ that is part of the lymphatic system, helps in production and removal of blood cells. Heart - It pumps the blood throughout the body.

Planarians are one of the types of flatworms belonging to the class Turbellaria. The excretory organs of planarians are flame cells. Flame cells are present in the phylum Platyhelminthes (flatworms). Flame cells are also known as solenocytes.These cells are irregular-shaped and hollow with pseudopodia processes.

Plant tissues are made up of different types of plant cells that are specialized for different functions. Three major types : Dermal tissue is the outermost layer of the plant and is made up of epidermal cells, which protect the plant from damage, water loss, and disease.
Vascular tissue is responsible for transporting water, nutrients, and other substances throughout the plant. It is made up of xylem and phloem cells, which form a network of tubes and vessels.
Ground tissue makes up the bulk of the plant and is responsible for carrying out many of the plant's metabolic functions. It is made up of parenchyma cells, collenchyma cells and sclerenchyma cells.